The present invention generally relates to the production test requirements for testing programmable termination resistor networks such as those used for Gigablaze® and other high speed serial interfaces.
The problem faced in the manufacturing test environment is that it is a non-ideal situation with respect to the contact resistance that occurs at multiple points between the tester's pin electronics and the actual device-under-test (DUT). These contact resistances are difficult to control at best, and cannot be completely eliminated. As such they contribute an error component to any resistance measurements that are to be made on the actual DUT. These errors in the measurements result in failing tests during the manufacturing test flow causing product yield issues.
The only existing solutions to the aforementioned problems involve the relaxation of test limits for the DUT, or the elimination of the test altogether. While this can address the manufacturing test problem, it provides the risk of shipping product out which is out of specification. Alternatively, the testing can be performed within the specified test limits, and the manufacturer is forced to accept any associated yield losses during the manufacturing test process.